Question

factorise : 4(x^2+1)+13(x^2+1)-12

Answer 1

correct equation:

4 (x^2 + 1 )^2 + 13 ( x^2 + 1 ) - 12

=4( x^2 + 1)^2 + 16 ( x^2 + 1 ) - 3 ( x^2 + 1 ) - 12

= 4 ( x^2 + 1 ) [ (x^2 + 1 )+ 4 ] - 3 [ (x^2 + 1) + 4 ]

= [ ( x^2 + 1 )+ 4 ) ] [ 4 ( x^2 + 1 ) - 3 ]

= ( x^2 + 1 + 4 ) ( 4 x^2 + 4 - 3 )

= ( x^2 + 5 ) ( 4 x^2 + 1 )

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